Thesis II
Thesis II - 3rd semester
LFA LOD improvement (secondary project)
Progress report on microfluidic device and surface modification
PDF
Week 2 (Aug 12 - Aug 16)
Week 3 (Aug 19 - Aug 23)
Week 4 (Aug 26 - Aug 30)
Week 5 (Sep 2 - Sep 6)
Week 6 (Sep 9 - Sep 13)
Week 7 (Sep 17 - Sep 20)
Week 8 (Sep 23 - Sep 27)
Week 9 (Sep 30 - Oct 4)
Week 10 (Oct 7 - Oct 11)
Week 11 (Oct 14 - Oct 18)
Week 12 (Oct 21 - Oct 25)
index

Week 12 (Oct 21 - Oct 25)

Monday

As proposed last week, it would be beneficial to decrease the width of the channel where the PDMS substrate is. However, this would lead to remake the substrates. For that reason, it was simply kept as it was.
Another attempt to fabricate the device was made, with the bottom layer still being 2mm thick.

20241021_134931.jpg

Device fabrication not possible with thick layers

Due to the thickness of the layers, it is not possible to press them in such a way that they remain adhered through the Pressure Sensitive Adhesive. Therefore, leakage is very likely to happen

Next steps
  • Fabricate a new device with a new 0.5mm thickness bottom layer with the hole for the PDMS substrate

Tuesday

As per the suggestion of the supervisor, the bottom layer of the new device was made from an acetate sheet instead of using 0.5mm thickness PMMA.
All the other dimensions were kept the same as last week's device.

20241022_132214.jpg

Resolved issues
  • It was possible to fabricate the device without leakage in the PSA
New issues
  • Due to the very small thickness of the acetate sheets, leakage is present around the PDMS substrate as it was in previous cases
  • Wobbling of the device during rotation causes instability and prevents tests to be done properly.
New assignments
  • Modify the overall device design to include a counterweight to balance out the device
  • Modify the overall design to incorporate properly the substrate without leakages

Wednesday

Some rings were designed to be placed around the hole to act in a similar manner as the thick 2mm layer that was previously being used.
Initially, it didn't seem to leak, but the wobbling of the device lead to inconclusive results.

Prevent wobbling
  • Similar weight on the opposite side of the circuit to act as counterweight

Friday

Implement a single circuit in the whole disc
  • The design of the device was made such that 2 circuits could be incorporated in a single disk
  • It should be possible to make the circuit (chambers) in the whole disk to reduce its diameter and use itself as counterweight
  • This would lead to have one circuit per disk
Table Of Contents
Week 12 (Oct 21 - Oct 25)
Monday
Tuesday
Wednesday
Friday